1. Field of the Invention
Embodiments of the present invention relate to laser welding. More particularly, embodiments of the present invention relate to a pressure unit to be used with a laser welding system that includes a rotating foot.
2. Description of the Related Art
A laser welding system may be used in a variety of applications, such as machine or automotive assembly, where the laser welding system may be used to weld workpiece materials, primarily metals, that are of different thicknesses or compositions or that require a small weld zone. The workpieces to be welded may abut one another and the weld may occur at the interface where the two pieces are joined. The laser welding system may also be used in joining workpieces that are superimposed, one on top of another. Typically, these workpieces are thin sheets of metal foil, which are layered one on another to form a structure.
The laser welding system may include a pressure foot to apply pressure to the top surface of the superimposed workpieces while the workpieces are welded together. The pressure foot must maintain contact with the workpieces while the laser head is in motion to make the weldments. Thus, the pressure foot must be able to move across the surface of the workpieces smoothly and still apply even pressure to the workpieces. Conventional pressure feet may be elongated and unable to apply pressure evenly to the work surface along the length of the weld pattern. Other pressure feet may include rollers or wheels that apply pressure to the surface while rolling. The wheels may include a variance in wheel height, wheel edge contour, or wheel alignment that can result in poor weld interface contact and reduced weld quality and strength. Furthermore, pressure feet that include wheels generally only support motion along one axis of movement.